By a remarkable feat of arms the veteran Spanish commander Mondragon had, October, 1572, reconquered several of the Zeeland islands.

His men on one occasion at ebb-tide marched across the channel which lies between South Beveland and the mainland, the water reaching up to their necks.

The patriot forces had since then recovered much of the lost ground, but Middelburg was strongly held, and so long as the Spaniards had command of the sea, was the key to the possession of Zeeland.

On January 29, 1574, the Sea-Beggars under Boisot attacked the Spanish fleet near Roemerswaal and after a bloody encounter gained a complete victory.

The siege of Middelburg was now pressed and Mondragon surrendered, February 18.